Vacuum motor sweeper



Sept. 18, 1962 FERRARI VACUUM MOTOR SWEEPER 3 Sheets-Sheet 1 Filed July 14. 1959 Sept. 18, 1962 FERRARI VACUUM MOTOR SWEEPER 3 SheetsSheet 2 Filed July 14. 1959 Sept. 18, 1962 FERRARI 3,054,130

VACUUM MOTOR SWEEPER Filed July 14. 1959 s Sheets-Sheet s hit rate 3,054,130 VACUUM MGTQR SWEEPER Luigi Ferrari, Genoa-Pegli, Italy, assignor to Firrna Belotti Industria Autogru-Altre Macchine, Genoa, Italy Filed July 14, 1959, Ser. No. 827,049 Claims priority, application Italy July 16, 1958 7 Claims. (Cl. 15-340) This invention relates to powerful and swift vacuum motor sweepers of a kind which is particularly adapted to sweep airport runways and landing strips clean of any dust, such term including in the present specification also sand, gravel and any loose materials which usually accumulate in considerable amounts on the runways of airports. It is universally known that such dust on runways constitutes a hindrance to the good functioning of the airport and often constitutes a danger to the takeoff or landing of aircraft.

The sweepers now in use on airports are of the vacuum type and are formed by a number of units each comprising a suction nozzle having a substantially rectangular mouth adapted to be moved with its sides in contact with a runway strip, the front side being constituted by a revolving cylindrical brush while the lateral sides are provided with a pair of parallel fixed brushes and the rear side is constituted by a somewhat flexible wall effectting a tight closure against the cleaned strip. A diagrammatic view of the nozzle part of this vacuum sweeper is illustrated in FIGURE 5 of the appended drawings from which the drawbacks of this design of vacuum sweeper are apparent and may be summarized as follows:

(a) The suction of the dust particles on a strip of the runway 11, during the forward running of the sweepercarrying and operating motor vehicle (arrow B) is effected from the front side, in the direction of the straight arrows, and from the lateral sides in the directions of the curved arrows. At the front of the nozzle a cylindrical brush is fitted which, by revolving in a direction opposite to that of the vehicle wheelsand which will be called the antiprogressing direction-stirs up the dust on the strip. A part of this dust is dispersed in the form of a whirlwind of dust, while another part is sucked across the revolving brush hairs, thin flexible metallic wires, or artificial hair of the brush, and is carried along by the air flow generated by a suction fan which entrains a part of this dust, as well as a part of the dust sucked across the side brushes into conventional dust filters and a dust bin (not shown).

(b) The coarsest and heaviest dust particles either are entangled between the brush hairs or are allowed to fall out of the air flow. In the latter case a central section of the strip is always covered with a substantial amount of coarse loose material which is not removed by the nozzle. Thus the swept runways are never very clean.

(c) In addition to this, due to the limited efficiency of the suction nozzle, the only way of removing as much as possible of the coarsest dust particles is to leave the dust for a substantially long time under the action of the suction air flow. Thus the conventional sweepers of the type above referred to are run at very low speeds of say 4 to 6 mph, so that cleaning a runway for usual aircraft requires from 10 to minutes, which is a considerable time where air and landing strips are intensively used.

The drawbecks of conventional vacuum sweepers are overcome, according to the invention, by given the suction nozzle a substantially isoceles triangular shape with the base of the triangle forward in the running direction of the nozzle, and by providing before said triangular part a hood-like rectangular projecting mouthpiece, whereby the revolving brush is housed at the rear end of said mouthpiece whose front or leading edge is free and extends, preferably at a level substantially below the axis of the revolving brush. Thus there is entrapped in the mouthpiece substantially the whole of the whirlwind of dust generated by the said revolving brush, and thus dust is immediately sucked across the revolving brush into the suction duct of a conventional vacuum cleaner.

Furthermore, in order to prevent the coarsest dust particles from collecting in a central position of the strip being swept, an upwardly sloping baffle plate is mounted in the triangular part of the nozzle upon which the brush throws the coarsest dust particles. This battle extends up to the inlet end of the suction duct. Accordingly, due to the converging nozzle walls and the provision of said battle, a restricted and more powerful suction area is formed beneath said bafile.

Thus, the coarsest dust particles, thrown by the revolving brush on the gently sloping baffle, remain in a powerful air flow until they are sucked into the suction duct, thus leaving the runway clean.

Due to the above provisions, it is no longer necessary to run the sweeper at low speed, and in practice the improved sweeper according to the invention may be run 4 to 5 times faster than the conventional sweepers. In practice the sweeper may effect its sweeping at speeds of over 25 m.p.h., thus sweeping a 2 km. runway strip in less than 3 minutes while doing its work much more perfectly.

The invention will be better understood from the following disclosure of one preferred embodiment of the invention which will be described with reference to the attached drawings, in which:

FIGURE 1 is a side elevation of a vacuum sweeper attached under a motor vehicle frame and provided with an improved suction nozzle according to the invention, the parts which are common to all conventional vacuum sweepers being omitted;

FIGURE 2 is a corresponding plan view, some parts being omitted or broken away;

FIGURE 3 is a longitudinal section on line IIIIII of FIGURE 2, viewed in the direction of the arrows and reversed;

FIGURE 4 is a bottom view of the nozzle illustrated in FIGURE 3; and

FIGURES 5 and 6 show diagrammatically the operation of a suction nozzle of conventional design and of a nozzle arrangement according to the invention, respectively.

In the following specification, the term material or dust includes all more or less fine loose materials such as sand, gravel, dust proper and generally all loose solids which collect on the airport runways and which must be removed periodically.

Although in the drawings only one suction nozzle has been shown, the vacuum sweepers usually comprise two or more of such nozzles which are suitably arranged and offset with respect to one another so as to cover the largest possible section of a runway.

As in conventional types, the nozzle is carried by or are suspended from a suitable motor car (not shown) on which also the air suction fans, the sleeve filters and all other control and driving fittings which are necessary for the purpose are mounted. The material sucked by the nozzles is deposited in a suitable dust bin mounted upstream with regards to the filters and may be discharged therefrom at will. In the filters the finest fraction of the material is collected, which in its turn is discharged in dust bins arranged for this purpose beneath the vertical filters. This arrangement is common to almost all con ventional vacuum sweepers and need not be shown or described.

With reference to FIGURES l to 4 of the drawings, the suction nozzle "1 comprises a substantially convex front section, which constitutes a mouthpiece having a substantially rectangular shape, viewed in plan in FIG. 4

and a rear section having in plan the form of a substantially isosceles triangle. The leading edge of the front section or mouthpiece is unobstructed and extends in proximity to the ground while its side edges and the adjoining sides of the triangular section or nozzle proper, are provided with brush-like extensions 770 on which the nozzle bears on the ground. Between the said mouthpiece and the base of the triangular nozzle a revolving cylindrical brush 8 is mounted, as in conventional vacuum sweepers. This brush extends crosswise of the triangular nozzle, substantially along the whole width of the front part thereof.

Inside of the triangular nozzle a baffle is mounted with its leading edge substantially parallel to the ground. Said bafile gently slopes upwardly and rearwardly from a point near the periphery of the revolving brush 8 to a point behind the apex of the triangular nozzle section, where said nozzle is provided with a tubular section 2 which is connected as by flange 3 to a duct 4 connected to the suction side of a fan mounted, as usual, on the motor cardiagrammatical ly indicated by the dotted line 5 in FIGURES 1 and 3-and under which the nozzle and related parts are hinged as will be better seen hereinafter.

The fan as well as the control members of the devices now to be described are substantially of a conventional type and in common use on vacuum sweepers and therefore need not to be described and shown.

As may be seen from FIGURES 1 and 3, the nozzle suspension and lifting means comprise a hydraulic cylinder 100 which is hinged by one end to a forked bracket 102 fastened to the vehicle frame 5 and in which a piston is slidably mounted, the rod .103. of which extends outside the free end of said cylinder 160. The end of said rod 103 is hinged to a lever arm 104 fastened to a transversal shaft 105 mounted in suitable bearings carried by brackets 165 fastened to frame 5. in proximity of its ends, the shaft 195 carries two lever arms 206 provided with forked ends to which a pair of draw bars 107 are hinged near their inner ends. The outer ends of said draw bars are hinged to lugs Ida-fastened to the nozzle 1. At the connecting points of the lever arms 266 to the draw bars .107, helical springs 109 are mounted upon the draw bars, the purpose of which springs is to permit small movement of the parts with respect to one another, for example in the case of unevenness of the ground or the like. The cushioning force of the springs m9 may be regulated by screwing of the nuts providedon the threaded ends of draw bars 107.

In its front part the nozzle 1 is spring-suspended at a predetermined and adjustable distance from the ground by means of a caster wheel 6, the pivot of which is supported by a fork 6 1 which is provided with a vertical swivel pivot 62 which is journalled in a corresponding bearing of a second outer fork 63 the arms of which are hinged to lugs 64 fastened to the nozzle 1.

In proximity of their hinge point to the lugs 64, the arms 63 are connected between them by a cross bar 65 provided intermediate its ends with a vertical hole through which a screw-threaded bolt 66 extends, the lower end of which is hinged to the underlying part of nozzle 1. Between the cross bar 65 and a washer mounted on a nut screwed at the upper end of bolt 66, a shock-absorbing elastic block 67 is mounted. By screwing more or less said nut on the bolt 66 the height of the suspended front end of the nozzle 1 from the ground is adjusted.

The cylindrical brush 8 is rockably supported by the nozzle 1. For this purpose, upon the nozzle 1 a pair of external space-d brackets 31 and 82 are fastened on the opposite nozzle sides, On these brackets the arms 85 and 8.6, which carry the shaft 87 of the cylindrical brush 8, are hinged by means of pivots 83 and 84. At least one of said arms, for example the arm 85, is provided with an upwardly extending nose 185 upon which a spring 83 acts which is fastened by one of its ends to the nozzle 1 so as to urge said lever 85, downwardly. On the pivot 83 there is also hinged an arm 183 on which the motor 89 which drives the cylindrical brush 8 is mounted. On the end of the shaft 87 of the cylindrical brush 8 which is nearer the motor 89, a pulley 93 is keyed which is connected through the belt 91 to the pulley 92 of the motor shaft. An expansion spring 93 is inserted between the motor-carrying arms 183 and the nose 185 of lever and acts so as to urge the motor 59 upwardly, thus tensioning the belt 91.

The nozzle 1 is provided with a pair of elongated slots 1% cut into its two sides so as to permit the passage therethrough of the shaft 87 of the cylindrical brush 8. At least one of the arms 85, 86, for example the arm 85, is provided with an abutment member 191 projecting from the side which lies opposite to that of the nose 185 and on which a set screw 192 acts, which is screwed into a lug provided externally on the nozzle so as to limit the downward swinging of lever arm 85 on pivot 83.

The operation of the machine thus described is as follows:

When the sweeper has to be carried onto the runway, the nozzle 1 is lifted out of contact with the ground. For this purpose fluid under pressure is introduced into the hydraulic cylinder 1% through the nipple at its free end, so as to cause the piston rod 163 to slide inwardly, viz. towards the hinged cylinder end. This inward sliding of rod 103 promotes the rocking of lever arm 104 through shaft 165 causes the lever arms 206 fastened thereto to swing upwardly and, by means of the draw bars 107, to lift the nozzle 1 clear of the ground. The operation is elfected in reverse direction when the sweeper comes to be on the runway to be cleaned.

In order to exactly adjust the height of the nozzle from the ground, adjustment may be made either of the nuts at the ends of the draw bars 107, or of the nut screwed on the bolt 66 at the front end of the nozzle. It is also possible to adjust the height of the cylindrical brush 8 with respect to the ground by screwing or unscrewing the set screw 192.

During the sweeping, the motor 89 is started and, through a transmission comprising pulleys and 92 and belt 91 drives the revolving brush 8 in the direction of the arrow A in FIG. 3, that is so that it rotates with respect to the ground in the same direction in which the nozzle is shifted. The spring 88 maintains the brush 8 always in contact with the ground.

During the running of the sweeper in the direction of arrow B, the revolving brush 8 stirs up the material present on the runway by urging same upwardly and forwardly. Due to the fact that the revolving brush is mounted inside of the front hood-like mouthpiece of the nozzle, no whirlwind of dust is formed at the exterior and the whole of the dust which has been stirred up is readily sucked by the air which penetrates both across the open front portion and across the brush-protected sides of said nozzle. Of course, the langest amount of air is sucked through the front part.

The heaviest material, which sticks to the revolving brush, is first lifted thereby and then thrown rearwardly and falls onto baflle 10 from where it is sucked; through the duct 2. Thus this coarse material which has been lifted by the revolving brush 8 does not fall again on the ground and is exposed for a longer time to the action of the air flow, thus making it unnecessary to reduce the speed of the sweeper in order to remove this heaviest material. The residual material which is blown towards the central part of nozzle 1 (see FIG. 6), is sucked by the air current induced through the side brushes 70 of the triangular nozzle part, and is concentrated in a narrower area within the nozzle, until it is sucked and conveyed into theconduit 2 by passing beneath the bafiie 10. Thus revolving brush 8, in combination with the bafile 10, serves also for dividing the air flow into two parts: an upper part which scavenges the top of the bafile 10 and one which cleans the ground under said baflie.

In FIGURE 6 there is shown the effect of the suction nozzle having the shape of an isosceles triangle, according to the invention, directly on the ground of a runway. By using this nozzle the air which is sucked from the sides blows the material into the central zone of the noz zle, into an area 211 which is becoming always narrower by proceeding rearwardly, until in the very rear end of the nozzle, the air flows induced across the brushes 70 ('FIGS. 1, 3 and 4) meet in a very restricted zone near the apex of the triangular nozzle and suck the whole material which has been pushed near that zone by said brushes 70, thus completely cleaning the said runway.

The particular form of the invention here described and illustrated in the accompanying drawings is presented only as an example of how the invention may be applied. Other forms, embodiments and applications of the invention, coming within the proper scope of the appended claims, will readily suggest themselves to those skilled in the sweeping art.

I claim:

1. A vacuum motor sweeper adapted to be carried by a motor vehicle having a source of vacuum thereon for sweeping airport runways or the like, said sweeper comprising a suction nozzle having in plan a substantially isosceles triangular shape with the base of the triangle forward in the direction in which said nozzle is moved in sweeping, substantially vertical fixed brushes extending downwardly from substantially equal opposite sides of said nozzle and converging toward the rear of the nozzle and said nozzle having a space between said brushes, a rotary cylindrical brush under said nozzle and extending along the base of the triangle formed by said nozzle, said vertical brushes and said cylindrical brush being adapted to bear upon the ground during a sweeping operation, said suction nozzle having a tubular section communicating with said nozzle space between said vertical brushes for connecting said space with the source of vacuum upon the motor vehicle, and a mouthpiece of said suction nozzle projecting forwardly of said cylindrical brush in the direction of sweeping movement, said mouthpiece having a top and opposite sides, and a forward end open to the air, said mouthpiece supporting downwardly extending brushes on the opposite sides thereof, the latter said brushes being adapted to bear upon the ground during a sweeping operation, whereby the whirlwind of dust particles stirred up by said cylindrical brush is contained in said mouthpiece and is readily sucked across said cylindrical brush into said nozzle space.

2. A vacuum motor sweeper according to claim 1, wherein said mouthpiece includes a frame, and a caster wheel carried by said frame for supporting said mouthpiece.

3. A vacuum motor sweeper according to claim 1, wherein said cylindrical brush includes an axial shaft, and said sweeper further comprises arm means pivotally mounted thereon and providing journals receiving the opposite ends of said brush shaft for said brush shaft to rotate, a motor having a drive shaft, pulleys on said shafts of the motor and cylindrical brush, an endless drive belt interconnecting said pulleys, and spring means biasing said pulleys away from each other and tensioning said belt.

4. A vacuum motor sweeper according to claim 1, wherein said sweeper further comprises wheel means for said sweeper to roll in contact with the ground, and suspension and lift means for the sweeper to be connected with a vehicle and thereafter lifted to bring said wheel means out of contact with the ground and lowered to bring said wheel means back into contact with the ground.

5. A vacuum motor sweeper adapted to be carried by a motor vehicle having a source of vacuum thereon for sweeping airport runways or the like, said sweeper comprising a suction nozzle having in plan a substantially isosceles triangular shape with the base of the triangle forward in the direction in which said nozzle is moved in sweeping, two substantially vertical fixed brushes each fitted along one of the equal sides of said nozzle extending downwardly therefrom, a cylindrical brush rotatably mounted transversely across the base of the triangle formed by said nozzle, said vertical fixed brushes and said cylindrical brush being adapted to bear upon the ground during a sweeping operation, said suction nozzle having a tubular section extending away from said brushes for connection with the source of vacuum upon the motor vehicle, and a bafile plate within said suction nozzle positioned with its leading edge substantially parallel to the ground and in close proximity to said cylindrical brush adjacent a diametrical horizontal plane thereof, said baffle plate extending upwardly from its leading edge along the whole nozzle width and substantially into the inlet of the tubular section of said nozzle extending away from said brushes.

6. A vacuum motor sweeper according to claim 5, wherein said sweeper includes a motor drivingly connected with said cylindrical brush for rotating said brush in a direction of rotation whereby the upper portion of said brush travels rearward and the lower portion of said brush travels forward.

7. A vacuum motor sweeper for sweeping airport runways or the like, said sweeper comprising: a suction nozzle including, in plan View, a front section of rectangular shape, a rear section substantially of the shape of an isosceles triangle with its base forward in the direction of sweeping and coinciding with the rear of said front section, a continuous top wall joining both of said sections, a suction conduit extending from said top wall substantially at the apex of said triangular section of said suction nozzle, and substantially vertical brushes fitted along the two lateral parallel sides of said front section and the two converging sides of said rear section of said nozzle; in combination with a cylindrical brush rotatively mounted transversely within said nozzle substantially in the area where said front and rear sections of said nozzle meet and spaced from the top wall, and a bafiile plate positioned within said triangular section of said nozzle with its leading edge extending substantially horizontally into close proximity to said cylindrical brush adjacent a diametrical horizontal plane thereof, said baffle plate extending across the whole nozzle width and upwardly from its leading edge substantially to the inlet of said suction conduit.

References Cited in the file of this patent UNITED STATES PATENTS 1,229,737 Furnas June 12, 1917 1,459,968 Bailly June 26, 1923 1,463,707 Koger July 31, 1923 1,975,380 Streich et a1 Oct. 2, 1934 2,740,984 Holt Apr. 10, 1956 2,830,510 Mariani et a1 Apr. 15, 1958 2,916,753 Redpath et al Dec. 15, 1959 FOREIGN PATENTS 220,252 Australia Feb. 17, 1959 598,900 Germany June 21, 1934 1,170,843 France Sept. 29, 1958 

